Isolation and structural characterization of the human 4F2 heavy-chain gene, an inducible gene involved in T-lymphocyte activation
Isolation and structural characterization of the human 4F2 heavy-chain gene, an inducible gene involved in T-lymphocyte activation
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DOI：
10.1128/mcb.8.9.3809-3819.1988
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发表时间：
1988-09
影响因子：
5.3
通讯作者：
Keith M. Gottesdiener;Beverly A. Karpinski;T. Lindsten;L. Jack;Strominger;Nancy H. Jones;'. C. B. Thompson;Jeffrey M. Leiden
中科院分区：
文献类型：
--
作者：
Keith M. Gottesdiener;Beverly A. Karpinski;T. Lindsten;L. Jack;Strominger;Nancy H. Jones;'. C. B. Thompson;Jeffrey M. Leiden
人4F2细胞表面抗原是由80 ~ 90 kDa的糖基化重链（4F2HC）和35 ~ 40 kDa的非糖基化轻链（4F2LC）组成的120千道尔顿（kDa）二硫键异二聚体。4F2属于诱导细胞表面分子家族，参与t淋巴细胞的活化和生长。为了更好地了解在静止T细胞和激活T细胞中控制4F2HC基因表达的分子机制，我们分离了一个4F2HC人类基因组克隆并对其进行了结构表征。4F2HC基因横跨11号染色体的8千碱基，由9个外显子组成。该基因的5'上游区域显示出管家基因的一些特征。它富含G+C，在外周血淋巴细胞DNA中低甲基化，含有Sp1转录因子的多个结合位点，而缺乏TATA或CCAAT序列。该基因的这一区域也显示出与其他几个诱导t细胞基因的序列同源性，包括白细胞介素-2、白细胞介素-2受体α链、二氢叶酸还原酶、胸苷激酶和转铁蛋白受体基因。4F2HC基因的255碱基对片段包含154碱基对的5'侧链序列，能够有效地促进细菌氯霉素乙酰转移酶基因在人Jurkat T细胞中的表达，这表明它包含启动子或增强子（或两者）序列。静息和凝集素激活T细胞的染色质结构分析显示，在4F2HC基因的5'侧翼和内含子1区域存在稳定的dna酶i超敏位点。尽管4F2HC基因表现出许多组成性表达基因的结构特征，凝集素介导的静息外周血T淋巴细胞活化导致4F2HC mRNA稳态水平的急剧增加。
The human 4F2 cell surface antigen is a 120-kilodalton (kDa) disulfide-linked heterodimer which is composed of an 80- to 90-kDa glycosylated heavy chain (4F2HC) and a 35- to 40-kDa nonglycosylated light chain (4F2LC). 4F2 belongs to a family of inducible cell surface molecules which are involved in T-lymphocyte activation and growth. To better understand the molecular mechanism(s) that controls 4F2HC gene expression in both resting and activated T cells, a 4F2HC human genomic clone was isolated and structurally characterized. The 4F2HC gene spans 8 kilobases of chromosome 11 and is composed of nine exons. The 5' upstream region of the gene displays several properties which are characteristic of housekeeping genes. It is G+C rich and hypomethylated in peripheral blood lymphocyte DNA and contains multiple binding sites for the Sp1 transcription factor while lacking TATA or CCAAT sequences. This region of the gene also displays sequence homologies with several other inducible T-cell genes, including the interleukin-2, interleukin-2 receptor alpha chain, dihydrofolate reductase, thymidine kinase, and transferrin receptor genes. A 255-base-pair fragment of the 4F2HC gene which contains 154 base pairs of the 5' flanking sequence was able to efficiently promote expression of the bacterial chloramphenicol acetyltransferase gene in human Jurkat T cells, indicating that it contains promoter or enhancer (or both) sequences. Analyses of chromatin structure in resting and lectin-activated T cells revealed the presence of stable DNase I-hypersensitive sites within both the 5' flanking and intron 1 regions of the 4F2HC gene. Although the 4F2HC gene displayed many of the structural features characteristic of a constitutively expressed gene, lectin-mediated activation of resting peripheral blood T lymphocytes resulted in a dramatic increase in steady-state levels of 4F2HC mRNA.